History

The predominant symptoms occurring during a seizure event determine the seizure type. These can be assessed from direct observation or from video recordings (see the video below), but this is relatively rare because most patients with epilepsy never have video recordings. Thus, in most situations, symptom assessment is based on history alone.

Note oral and hand automatisms at initiation of event. Patient is not following commands or answering questions during the event.

For this reason, a purely semiologic classification has been proposed and is in use at some centers.
[24, 25, 26] In this system, seizure types include autonomic, dialeptic, simple motor (clonic, tonic, tonic-clonic, epileptic spasm, myoclonic, versive), complex motor (automotor, hypermotor, gelastic), and negative (aphasic, astatic, atonic, akinetic, hypomotor, negative myoclonic). Focal impaired awareness seizures, as defined by the International League Against Epilepsy (ILAE) classification can be equivalent to various categories of the semiologic classification.
[1]

A thorough history should be obtained from the patient, the family members, and any relevant witnesses. It is the most important part of investigating a seizure event.

Question the patient regarding any family history of seizures, febrile seizures as an infant, or previous history of traumatic or other brain insults, which may place the patient at a higher risk for seizures. If the patient has a history of seizures, include his or her responses to previous anticonvulsants or surgery and the results of previous cranial magnetic resonance imaging (MRI), electroencephalography (EEG), and video-EEG recordings.

Focal impaired awareness seizures typically last 30 seconds to 2 minutes. Longer seizures may occur when seizures become generalized with full body convulsions or transform to a state of partial status epilepticus.

Aura

An aura is a subjective sensation and is a simple partial seizure (ie, the initial part during which the patient is aware). Typically, it is of brief duration, rarely lasting longer than seconds. Determining the type of aura present is critical for identifying the site of cortical onset. Eight different varieties are recognized: somatosensory, visual, auditory, gustatory, olfactory, autonomic, abdominal, and psychic.

Parietal lobe seizures may begin with a contralateral sensation, usually of the positive type (electrical sensation, tingling). Occipital lobe seizures may begin with contralateral visual changes, usually of the positive type, such as colored lines, spots, or shapes, or even a loss of vision. Temporal-parietal-occipital seizures may produce more formed auras.

Impaired consciousness

Focal impaired awareness seizures, in the ILAE classification, are defined by impairment of consciousness.
[1] This implies decreased responsiveness and awareness of one’s self and surroundings. Usually, during a focal impaired awareness seizure, a patient is unresponsive and does not remember events that occurred.

Consciousness may not be impaired completely, however. Although patients typically do not respond to external stimuli, they may make simple verbal responses, follow simple commands, or continue to perform simple or, less commonly, complex motor behaviors (eg, operating a car). Impairments in consciousness should be contrasted with psychic automatisms, in which the patient experiences intense feelings of strangeness.

Focal impaired awareness seizures are roughly equivalent to what used to be known as psychomotor seizures. In the semiologic classification, they are equivalent to automotor seizures (automatisms), whereas seizures with alteration of consciousness without motor phenomena are known as dialeptic seizures.

Automatisms

Automatisms are nonpurposeful, stereotyped, and repetitive behaviors that commonly accompany focal impaired awareness seizures (in the semiologic classification, they define automotor seizures). The behavior is inappropriate for the situation. Patients are usually amnestic to their automatisms. Verbal automatisms range from simple vocalizations, such as moaning, to more complex, comprehensible, stereotyped speech.

Automatisms can also be more elaborate, coordinated movements involving bilateral extremities. Examples of complex motor automatisms are cycling movements of the legs and stereotyped swimming movements. Bizarre automatisms, such as alternating limb movements, right-to-left head rolling, or sexual automatisms, may occur with frontal lobe seizures.

Automatisms may also occur during nonepileptic states of confusion (eg, metabolic encephalopathy), after ictus, and during absence seizures, especially when prolonged.

Temporal versus extratemporal seizures

Focal impaired awareness seizures can arise from any location but most commonly arise from the temporal lobe (60%). Temporal lobe seizures have highly specific behaviors as compared with extratemporal seizures.

Focal impaired awareness seizures of temporal lobe origin often begin with a motionless stare followed by oral or manual automatisms. Frontal lobe seizures often begin with vigorous motor automatisms or stereotyped clonic or tonic activity.
[3] Extratemporal lobe seizures may spread quickly to the frontal lobe and produce motor behaviors similar to those associated with focal impaired awareness seizures of the frontal lobe.

Physical Examination

The physical examination is directed so as to elucidate focal cortical neurologic findings, such as aphasia, unilateral neglect, apraxia, or unilateral signs. In the vast majority of patients with focal epilepsies and focal impaired awareness seizures, the neurologic examination yields normal results.

French J, Smith M, Faught E, Brown L. Practice advisory: The use of felbamate in the treatment of patients with intractable epilepsy: report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 1999 May 12. 52(8):1540-5. [Medline].

American Academy of Neurology. Practice parameter: a guideline for discontinuing antiepileptic drugs in seizure-free patients--summary statement. Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 1996 Aug. 47(2):600-2. [Medline].